1. Field of the Invention
The invention relates to an electrical connection device constituted by an active socket and a plug provided with at least one contact that is designed to co-operate with an opposing contact of the socket arranged in insulation, which insulation is provided with at least one passage for introducing said contact of the plug while coupling the plug with the socket.
The connection devices to which the invention relates are in particular plug and socket-outlets, cable couplers, and appliance couplers.
2. Discussion of Background Information
Such connection devices present numerous problems for solving as a function of their applications, and in particular safety problems.
In particular, in order to comply with the standards that are in force for guaranteeing the safety of people and property, it is known that electrical appliances must provide at least some minimum degree of protection against access to live parts.
In order to verify that such protection is indeed provided, use is made of an articulated test finger as defined by a standard.
Testing consists in not being able to make contact between the standardized test finger and the live parts of the appliance under test while attempting to insert the test finger in all possible positions, said test being particularly difficult to satisfy when high-current electricity is involved.
In addition, it is also clear that a plug must not be capable of coupling with a socket unless they are mutually electrically compatible so that the currents and/or voltages and/or electrical power levels correspond between the two connection elements.
For this purpose, it is desired to use mechanical means to prevent two connection elements that are mutually electrically incompatible being coupled together, with this being made more difficult by the fact that the component parts of such elements are standardized, in particular for reasons of cost.
Furthermore, certain connection devices require or recommend the use of pilot contacts serving, for example, to control the flow of electricity remotely. Unfortunately, conventional devices, and in particular single-pole appliance couplers, often do not have sufficient space for receiving pilot contacts.
The inventors have devised a contact that serves specifically to solve several of the problems posed simultaneously.
Document DE-196 38 157 and members of its family, such as document U.S. Pat. No. 5,759,069 A describe an electrical connection device for audio or similar types of appliance in which the problems to be solved do not relate to safety nor to the other problems mentioned above, because of the low currents used.